Biblical criticism is the use of critical analysis to understand and explain the Bible without appealing to the supernatural. During the eighteenth century, when it began as historical-biblical criticism, it was based on two distinguishing characteristics: (1) the scientific concern to avoid dogma and bias by applying a neutral, non-sectarian, reason-based judgment to the study of the Bible, and (2) the belief that the reconstruction of the historical events behind the texts, as well as the history of how the texts themselves developed, would lead to a correct understanding of the Bible. This sets it apart from earlier, pre-critical methods; from the anti-critical methods of those who oppose criticism-based study; from the post-critical orientation of later scholarship; and from the multiple distinct schools of criticism into which it evolved in the late twentieth and early twenty-first centuries.

Deism is the philosophical position and rationalistic theology that generally rejects revelation as a source of divine knowledge and asserts that empirical reason and observation of the natural world are exclusively logical, reliable, and sufficient to determine the existence of a Supreme Being as the creator of the universe. More simply stated, Deism is the belief in the existence of God, solely based on rational thought without any reliance on revealed religions or religious authority. Deism emphasizes the concept of natural theology—that is, God's existence is revealed through nature.